Alarm-circuit system



17, 1929. G, C, sNY-DERS ET AL 1,740,123

ALARM CIRCUIT SYSTEM lFiled oct. 19. 1927 2 sheets-sheet 1 HSf/z C G Q ,/nlfaaors;

.DCC- 17, 1929. G. c. sNYDERs ET AL. 1,740,123

ALARM CIRCUIT SYSTEM Filed o't. 19. 1927 2 sheets-sheer 2 Patented Dec. .17, 19.29-

UNITED ySTA'Illf-ZS .PATENT l(D'PIT-"ICE eYsDEnrus coaNELrs snYDEEs, connELrUs coanrn, Jn., JAN' 'VAN DE "KAMP, AND CHARLES EDWARD ADRIANUS MAITLAND, or AMSTERDAM, NETHERLANDS ALARM-CIRCUIT SYSTEM Application filled October 19, 1927,-.Seria1 ld-227,150, and in Germany April 26, 1926.

Our invention relates to improvements in alarm circuit systems and is intended more particularly for alarm installations with a large number of alarm sending stations, for instance tirev alarm plants Vin large cities.

it has already been proposed, for instance in Patent No. 697,065, to subdivide the alarm sending stations ot extensive systems into a plurality ot districts and to pro-vide a distributing station for each district. In .these distributing stations the lines arriving from the sending stations of a `district are collected vand in one or a plurality of bunches passed on tothe central alarm receiving station. In this system or arrangement the danger arises,

o that in the event of breakdowns of lines between the distributing stations and the alarm receiving station the reception of an ala-rm might be prevented although parallel lines are disengaged and free from detects.

rEhe principal object of our invention is to eliminate this drawback. life attain this end in view by providing/at the distributing stations automatic means adapted to connect the line of an alarm sendingstation with a disengaged trunk line leading to the alarm receiving station.

Another object ot our invention is to supply means whereby'any number ottrunk lines be provided between the distributing stations in the districts and the receiving station.

For economical reasons, however, the number ot trunk lines between the distributing stations and the alarm receiving station should preferably be less than the number ot the alarm sending stations connected with the distributing stations. The service reliability ot vthe alarm plant is not reduced thereby.

A further object of our invention is to connect each alarm sending station with a free trunk line by the automat-ic means and it appears very unlikely lthat a call should be sent simultaneously trom all alarm sending stations 'of a district.

As a matterl of course the layout may be such that the number of trunk lines 'between vthe `distributing stations and the alarm r'eceivingstations iscqual to the numberoil the alarm vsending stations connected with the distributing stations. The provision of the yautomatically operating connecting ymeans has the result in this case also that in case of a breakdown of Ione or a number of :trunk lines the transmission ot the alarm signal to the alarm receiving station is ensured, which would not be the case in the event of the continuous wiring ot .the lines of the alarmsendvembodiment of our invention lby' way ot example. A

Fig'. l is a diagram ot the system of an alarm plant, and l Fig. 2 shows diagrammaticallly `the manner ot operation `of the means provided at the distributing stations and the central signal receiving station. l

Like parts are indicated by like letters of reference 'in both figures of the drawings.

Signaling boxes 4J, forv example those known in the art as sector boxes, which may be wound and which will set in motion a signal 'wheel when released, may be utilized at the various sending stations.

The. selectors VVland W2 shown in Figure 2,1a're intended to indicate a calling alarm giving' station, for instance 'the alarm giving station AGSMSL atthe alarm receiving station The selector W1 with the switch arms w11, wlfywl and 'w14 isa step by step switch gear of the well known construction. The switchv arm w14 controls the circuits of the several hundreds lamps of the alarm giving stations.- The selector W2 is a littingerotating selector of the Strowger type. The switch larm e021 controls the circuit of the tens lamps, and the switch arm w22 the circuit ot the unit lamps of the alarm giving stations. In the case. of a call 'from an alarm giving station, the switch arm w28 will cause the lighting of a lamp which indicates to the c-licial at the alarm receiving station HBVV, in which district the calling alarm station is situated. The selectors lVl and W2 are individually allotted to the connection line constituted by the conductors a, l) and 0 so that there is a separate pair of selectors W71 and W2 for each trunlr line from the distributing station to the central alarm station. lt is apparent that any individual selector W1 will only have to respond to calls from a single distributing station. The distributing stations may be considered to have numbers, the station VSTl in this case being number 4L or in Zone il. There-tore when any call comes in to W2, the hundreds digit has already been effect-ive in picking out the selector l corresponding to Zone 4 and also in stepping arm w13 to the fourth position, through which contact, W2 is energized for the remaining two digits and so a selector `W2 is picked out which corresponds to Zone il. When the other two digits are sent, they serve to properly position w21, w22 and w23 to give the necessary number and location of the calling station.

The lamps H4, Z3 and El are arranged in a single bank and are used jointly by all the selectors and all the alarm sending stations. Should two or more calls be sent in simultaneously there will be no interference one with the other for each will operate separate selectors Wl and W2 and the operator can then answer' lirst one and then the other by inserting his telephone set Abr-li into the jack indicated by the lamps LH and Lllll which will, as explained more in detail later, operate relay L to close the circuits to the lamp bank. The operation of the system will now be described in detail. ln the circuit diagram Fig. 2 all relays are shown in deenergiaed condition. In this position a current flows from the distributing station VSH to the alarm transmitting station AGSzfl as ollows: earth, battery, relay A, current impulselcontact 4J, relay Q, relay B, earth. ln this circuit only the relay B and the relay Q are excited. The relay A does not respond as yet on account of the high-ohmic relay Q.

At each alarm giving station there is an apparatus (impulse sender) of any suitable construction (shown diagrammatically in Fig. 2 at 4J). By this apparatus the contacts 170, 270 and 4J are operated in any appropriate manner. Before transmitting of impulses b-y contact 4J begins the contacts llc and 27.#l are already operated.

If now the calling apparatus is operated at the alarm transmitting station AGSMQA which by the emission of a predetermined number of current impulses transmits to the alarm receiving station HB'W the number appertaining to this transmitting station (in our example the No. 431), the contacts Us, 270 are operated. By the operaton oit the contact l/a the above described supervisory closed circuit of the alarm transmit ing station 'Gtltlll is altered, the relay Q switched oli', the relay B short circuited and the relay A directly connected to earth. rlhe relay B which was energized in the normal condition of the olantis deenergized and lights up the lamp L at the distributing` station VSzfl by means of bach contact 19o. The fact that the relay Q falls back ellects the switching in of a visible signal SZ at they alarm 'transmitting station 4:31. The relay A which in the before described supervisory closed circuitwas not excited due to the high resistance oi Vne relay Q, is now excited along the following path: earth, contact 17e, a-conductor, contact 4J, relay A, battery, earth. By closing the Contact 270 the speaking apparatus N of the alarm transmitting station is connected into the trunk.

Upon the operation of the relay A a circuit for the relay nl is closed: earth, iront contact 8a, relay Al, back contact 93a, battery, earth. The relay nl closes its contact Yal and prepares a circuit iior the relay A2. From he alarm transmitting station AGStlSl the iirst current impul. e series (in our example the number 4) is now sent by the current impulse contact 4J. After the emission ot' the iirst current impulse the relay A. becomes deenergized and the. relay A2 is excited by a current taking the following path ;v earth, back contact 8a, front contact 7&1, relay n.2, back contact 98a, battery, earth. The relays Al and A2 are slow-release relays and consequently remain ex 'ited during the sending of current impulses by the relay A. lith its Contact 6&2 the relay A2 closes a holding circuit or itself independently of relay A; earth, Yitront Contact (m2, liront contact Tal, relay A2, baclr contact 98a, battery, earth.

lf the relay'A is excited due to a breakdown, for instance, by a short-circuito the a-conductor, the contact Sa is operated and remains in its operative state. The excitation of the relay A2 and a transmission of switching operations to the alarm receiving station HBlW is prevented thereby. ln the event of a breakdown only the relay Al of the two relays Al and i2 thus is Voperated and by t ie Contact 2lal a lamp Lg is made to lightv up reporting the breakdown which has developed at the distributing station VS. rlhe circuit for the lamp Lg is as follows: earth, front contact 21661, back contact 22a2, lamp `Lg, battery, earth. Due to the earth conneclamp Lr. A short circuit between both con-l lll() ductor's'l causes a direct closing of the abr-loop. In that case the relay A rand the relay B are excited, and the relay A brings about the contact 13a2 it closes the circuit :tor the rotary magnet D1 et the 'line finder AS: earth, baclr contact 12ga, trent contact 13a2, cZ-conductor, b-wiper of the line-finder, position O, rotary magnet Dl, back contact 14391, automatic circuit-breaker UBI batter earth. 7 7 1 If the rotary magnet Ill has operated tne line finder AS b one sten it 1s excited in the l a following manner: earth, cZ-'wiper oit' the line finder AS, rotary magnet D1, back contact. 1Llp1, automatic circuit-breaker UBI, battery,

earth. The line iinder AS is thus intermittently stepped forward until it has found the callingv alarm transmitting station AGStll. In this position it closes the test circuit across the c-conductor: earth, front contact 10a2, relay Sa, c-co-nductor, c-wiper of' the line finder AS, windings I and II of the test relay P1, c-conductor of the trunk line VLI. windings II and I of the test relay P2, bacl Contact 17], battery, earth. The windings II of the test relays P2 and P1 are short-circuited by the contacts 15,191 and 16292 and thus the trunk line VLl is blocked against a call from another alarm giving station in a manner to be described more in detail hereafter. The contact 14291 interrupts simultaneously the circuit for the rotary magnet D1 of the line finder whereby the latter is rendered inoperative. With its contact 118e the relay Sa closes a holding circuit for the test line.

The alarm giving station AGSISI is connected in multiple connection to a number of call finders. This arrangement is not fully shown in Figure 2. It for instance when the alarm giving station AG'SAl is calling, the call finder AS shown in Figure 2 is already engaged7 the circuit for the rotating magnet D1 of the call finder AS will be opened by the contact 14201, and the call finder AS cannot be started. A free or disengaged call finder to which is also connected the alarm giving station AGStlSl, starts and searches for the calling alarm giving station.

If the connection line starting from the call finder. AS, leading from the distributing station VS1/1 to the alarm receiving station HBV and constituted by the conductors a, b' and c, should become detective, the call finder AS will not be able to find a calling alarm giving station and connect it to the defective connection line because the line 0 will be broken and therefore relays P1 and P2 will not energize.

It the call finder AS has found for instance the calling alarm giving station AGSz/l and connected it to the connection line leading to the alarm receiving station HBl/V, the high resistance windings II of the testing relays P1 and P2 'will be short circuited in 'the well known manner. The result of this short circuit will be that no further call finders connected in parallel to the call finder AS, will be able to become switched on to the same connection line oft the alarm giving station AGStLlSl. rlhe testing relays of the remaining call finders cannot be excited when they Contact with a line already in use because they include the high resistance coils II which will be placed in parallel with low resistance coils I oit the test relay already in use. There is not suflicient voltage drop across the coils I to operate the marginal coils II. This second line finder is shown as comprising the line c and relays P1 and P2 which are identical with relays P1 and P2. The line continues to the corresponding terminal 177' of a second relay Il" and through battery to ground, thus making the relays P1 and P2 in parallel with P1 and P2 when two call finders contact with the same sending station. For a full disclosure of this operation ot blocking a trunk line, reference may be had to German Patent 300,949.

The drawing shows completely the apparatus tor only one call finder AS but it will be understood that the call finders associated with all the 'trunk lines are multipled and all are set into operation when any calling sending station sends out its first conditioning impulse. The contacts 1OA2 of relay A2 close a circuit through relay Sa and the line over which the signal ultimately will be sent as well as a circuit 4tor all the other relays Sa of the other trunk lines c. Likewise, contacts 13a2 of relay A2 close a circuit tor the rotary magnet D1 as well as for all the other magnets D1 of the trunk lines c. These rotary magnets D1 will continue to operate the call finders not in use as long as relay A2 is energized and will. only stop when that relay is deenergized or when they come in contact with a calling sending station. The call finders may be returned to normal position by the deenergization of the relay P1 which closes a self-interrupting circuit for steppingmagA net D1 through the bank of contacts CZ.

The relay P2 opens by means of its Contact 23292 the exciter circuit tor the release niagnet M of the rotary selector `W2 at the 'ala receiving station I-IBW'. By closing the contact 43372 the lamp LII is made to light up and indicates at the alarm receiving station that an alarm transmitting station has been con- CII nccted With it. The relay P2 closes Withits Contact 18292 the exciting circuit tor the impulse relay ot the alarm receiving station: earth, back contact 5a, inductive coils D1", aand wiper ont the line nder AS, aand Zi-conductors ot the trunk V111, inductive coils D11, current impulse relay l, front contact- 18292, battery, earth. rilhe inductive coils D11 merely serve to establish a speaking communication between the operator ot the alarm receiving station HBlV and the alarm transmitting station ."rGStdll. Vllhe Contact 5a transmits the current impulses from the alarm transmitting station tothe relay l. 'lhe relay A at the distributing station VS2/1 'tollovvs the current impulses emitted by the alarm transmitting station and by opening and closing of the Contact 5a the current impulse is transmitted to the relay I at the alarm receiving station HBVV. Bv the closing et Contact 251' the relay El, constructed as a slow-release relay, is excited across: earth, relay K1, iront Contact 251', battery, earth. The relay K1 remains excited during the sending ot a series of current impulses and opens its contact 36701, so that the relays V1, V2 and V3 are unable to become energized during this time. By means of its contact 29a' the relay transmits 'the current impulses reccived to the rotary magnet D3 ot the selector lV 1: earth, rotary magnet D3, baclr Contact 2801, 'front contact 292, battery, earth. fitter the tiret impulse series is finished the relay K1 becomes deenergized and closes with its back contact 36761 a circuit oi the relay V1: earth, aclr contact 36761, back contact 33111, relay V1, back contact 307", Wiper w13 of the selector v"Vl, battery, earth.

The rotary magnet D3 has zitter its first impulse series (in our example consisting oit tour current impulses) stepped the selector ffl up the predetermined (in our example the fourth) vhundreds lamp Het across its Wiper lVle. The Wipers of the selector XV, as Well as those of the tinder switches, are prcteraoly of the double arm variety.

By its contact 331A the relay V1 has closed a holding circuit for itself, by its contact 28111 it deenergizes the rotary magnet D3 and operates the vertical magnet l-l. lVhen sending the second current impulse series the relay K1 is reexcited and opens its contact 36721. The vertical magnet H is consequently excited by the -following circuit: earth, magnet H, back contact 27122 front contact 28'01, current impulse contact 2911, battery, earth. The vertical magnet raises the selector W 2 into the desired decade, tor,

and closes, and since the selector W2 is raised out of its inoperative position and consequently the contact 3170 is closed, a circuit tor the relay V2 is completed: earth, contact 36701, contact- 3/1112, contact 3170, relay V2, contact 30], Wiper w13 of the selector Vil, battery, earth. rIhe relay V2 closes With its contact 341122 a holding circuit 'for itself and With its contact 27122 it deenergizes the vertical magnet and operates the rotary magnet. During the sending of the third series of current impulses the relay K1 is excited again and thus the contact 36701 opened. The third series of current impulses now transmits itself to the rotary magnet D2 along the following circuit: earth, magnet D2, back contact 26118, 'front contact 27V2, iront contact 28121, current impulse contact 29a', battery, earth. In correspondence with the series of current impulses the rotary magnet D2 turns the selector VJ2 into the stepped decade. Since the relay K1 is deenergized again after the third series ot current impulses is linished and the selector `W2 has been turned into the correct position, the relay VS is now excited across the o normal spring 3271;: earth, back contact 36701, baclr contact olil .normal spring 8270, relay V3, contact et rest 307i, Wiper w13 of the selector lV 1, battery, earth. The relay V3 produces a holding circuit for itseltl by closing its contact 35123, With its contact 26113 it deenergizes the rotary magnet D2 ot the selector `W2 and prepares a circuit Jfor the relay K2.

By its contact 14113 the relay V3 closes a circuit for the lamp LUI, the lighting up ot which indicates to the operator at the alarm receiving station that the transmission of the alarm is finished. A

The contacts of the Wiper 1023 ot the selector V12 are connected with a lamp panel, Which represents a plan of the entire layout and indicates to the operator at the central alarm station 'from which point ot the city the call has been sent. By closing the contact 46113 this lamp is lighted up, since the selector W2 is stepped up a delinite lamp LL431, and the alarm transmitting station unequivocally indicated.

It after the sending of an alarm from the alarm transmitting station AGStll this transmitting station is returned again into the inoperative state, before the operator of the receiving station has been able to get into communication With it by means of his telephone Aon, the contact 5a is closed due to the deenergizing ot' the relay A at the distributing station VS21 and the relay I is excited. The circuit for the relay K2 is consequently closed: earth, relay K2, front contact 26113, front contact 2Y1J2, front contact 28121, front contact 29Z, battery, earth.- By the closing ot' its contact 42702 the relay K2 causes the lamp LI to light up and indicates to the operator at the alarm receiving station that after the sending of the alarm signal this alarm station has been abandoned again.

For the purpose of getting into communi* cation With the connected alarm transmitting station the operator at the alarm receiving station inserts the plug of his calling up apparatus AEA into the jack, whereby the relay L is excited: earth, plug jack, relay L, battery, earth. The relay L effects the closing of its contacts 3W, 40Z and 41E Whereby the circuits for the lamps H4, Z3 and El are closed and the number of the connected alarm transmitting` station 431 appears in the lamp panel.

After the operator at the alarm receiving station has noted the report, he depresses the release key AT. The relay F is then eX- cited along the following circuit: earth, relay F, Wiper w12 of the selector W1, release key AT, battery, earth. SSf the relay closes a holding` circuit for itself. By opening the contact 30f the relays Vl, V2 and V3 are deenergized. By the contact 39]C the rotary magnet D3 is connected With the automatic circuit-breaker UB2 which turns the selector Vl intermittently forward into the position of rest across the following circuit: earth, rotary magnet D3, Wiper w11 of the selector llVl, front contact 39f, vautomatic circuit-breaker UB2, battery, earth. By opening the contact 17]e the test current passing across the connecting line VLl is broken and the relays Sa, Pl and P2 deenergizing. By the deenergization of the relay P2 the release magnet M of the selector `W2 is energized in across the back contact 23p2 which returns the selector into the position of rest. By closing the contact 45] the lamp LlV is made to light up Which' for the operator at the alarm receiving station serves as a control or check for the fact, that the selector W1 has been turned back into the position of rest, since when the selector Wl is turned into the position of rest the circuit for the relay F is interrupted and the lamp LIV goes out again.

The selector V2 is so constructed that its Wiper w21 runs across banks of contacts which are directly connected in the direction of rotation of the selector, While the Wiper w22 traverses banks of contacts, Which are connected through in the vertical direction of the selector. ln this Way the result is attained that a lamp panel of 3 10 lamps is able to control unequivocally a range of numbers from l to i000.

Various modifications and changes may be made Without departing from the spirit and the scope of the invention, and We desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

Having now particularly described and as- `With its contactA certained the nature yof our said invention ing station, trunk lines connecting said dis-V tributing station with the alarm receivingV station, automatic means at said distributing station responsive to the initial operation of said transmitting 'means for connecting a calling station with a disengaged trunk line leading to the alarm receiving station, and controlling` means in said distributing station operated by the said automatic means indicating the connection of a trunk line With the line of an alarm sending station.

2. An alarm circuit system comprising alarm sending stations, a distributing station, a central receiving station, circuits connecting said sending stations With the distributing station, trunk lines connecting the distributing station with the alarm receiving station, means at each sending station for changing the resistance of the circuit connecting` the sending station With the distributing station and for thereafter transmitting impulses over said circuit, and means responsive to the change of resistance of said circuit and the transmission of impulses thereover for automatically connecting said circuit to a disengaged trunk line leading to the central station, whereby said means Will be nonresponsive to a mere change of the resistance of the circuit due to a defect of the circuit which Will either open or short circuit the circuit.

3. An alarm circuit system comprising alarm sending stations each having means for transmitting impulses, a distributing station, circuits connecting said sending stations with the distributing station, an alarm receiving station, trunk lines connecting ,said distributing station With the alarm receiving station, automatic means at said distributing station responsive to the initial operation of said transmitting` means for connecting a calling station With a disengaged trunk line leadingto the alarm receiving station, and controlling means at the receiving station operated by the taking of a particular trunk line for use for indicating such trunk line.

4. An alarm circuit system comprising alarm sending stations, a distributing station, a central receiving station, circuits connecting said sending station With the distributing` station, trunk lines connecting the distributing station with the alarm receiving station, means at each sending station for changing the resistance of the circuit connecting the sending station With the distributing station and for thereafter transmitting impulses thereover, means responsive to the change of resistance of said circuit and the transmission of impulses thereover for automatically connecting said circuit to a disengagecl trunk line, and manually operative "means in the receiving station toestablish connection With the sending station through the trunk line taken for use, and indicating means responsive to the restoration of the alarm station circuit to normal for indicating abandonment of the alarm sending station.

In testimony whereof We aiix our signa-- tures.

GYSBERTUS CORNELIS SNYDERS. CORNELIUS GORDYN, Jr. JAN van de KAMP. CHARLES EDWARD ADRIANUS MAITLAND. 

